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valiDation of Radical Engine Architecture systeMs

Tags: Air

State of the Art - Background

The DREAM project is the response of the aero-engine community to commercial and environmental pressures that have come about mainly as a result of two main factors:

- The political pressure to reduce CO2 emissions has increased considerably since the publication of the ACARE goals (ACARE: Advisory Council for Aeronautics Research in Europe).

- Hydrocarbon fuel ressources are finite; recent fuel prices suffered from large oscillations with

an overall trend upwards.

Consequently DREAM is studying a range of completely novel designs for both contra-rotating open rotors and turbofans developing novel engine systems on top of the technologies issued from the EU funded EEFAE, NEWAC and VITAL projects and validating the use of alternative fuels in these aero engines to demonstrate green house gas emission reduction.


The objectives are to reduce:

- CO2 by 9 % over and above the FP7 Integrated Project VITAL or the FP5 Technology Platform EEFAE Technology Readiness Level (TRL) 4/5 (7 % better than ACARE or 27 % better than year 2000 engine),

- Noise by 3 dB per operation point (~ -9dB cumulated on 3 certification points) versus the year 2000 engine references at TRL4 with improved methods, materials and techniques developed on past and existing noise programmes,

- NOX will be reduced accordingly with engine specific fuel burn reduction.

Description of Work

DREAM comprises of 6 sub-programmes:-

0 - Management and dissemination

Ensures the overall programme management and dissemination

1 - Whole Engine Architecture

Specification and assessment of each architecture concept

- Defines the aircraft application context

- Ensures the overall consistency of DREAM results

- Assesses the benefits of the DREAM engine technologies and architectures that have the potential to go beyond the ACARE objectives for fuel consumption

- Considers both specification and assessment of each architecture concept, from the common point of view of aircraft environmental and technical objectives

2 - Geared Open Rotor

Development of an advanced geared open rotor concept in a pusher configuration

- Specifies the engine architecture

- Test blades rig tested in both high and low speed wind tunnels to enable the acquisition of both aerodynamic and acoustic data

- Performs the parametric studies with the addition of a pylon. Comparable 'isolated' and 'installed' aerodynamic and acoustic data will be generated, with acoustic data again captured and analysed.

- Examines a range of mechanical design options for variable pitch open rotors and the integration of the control mechanism with the system.

- Develops an Optimised Power Turbine module for the geared open rotor configuration including rig testing to support performance predictions.

- Design the hot rear support structure

3 - Direct Drive Open Rotor

Development of the advanced direct drive open rotor

- Specifies the engine architecture

- Define several advanced propfans including one reference for test rig calibration

- Acquire both acoustic and performance test data of the above propfans at low and high speed conditions in wind tunnels

- Develop the most innovative features of the stator-less counter-rotating turbine

- Define an advanced high-speed low pressure compressor dedicated to the open rotor engine

- Validate the advanced aero concepts on a one stage rig

4 - Innovative Systems

Provides enabling technologies for low weight and low cost future engines leading to an efficiency improvement of 0.5 % by adding innovative functionality and active solutions for turbines:

- Active vibration control engine structure with piezo actuator damping systems

- Elastomer damping rings for passive vibration control and cost efficiency

- Innovative mid turbine frame configurations with optimized aerodynamics, structural mechanics and materials

- Active boundary layer control for high speed flow to improve the efficiency of low pressure turbines

- Closed-loop active clearance control to improve the low pressure turbine running clearances

5 - Alternative Fuels Demonstration

Demonstrates that alternative fuels can be used in modern aircraft and engines

- Demonstrates the performance of an existing available fuel (XTL type or 3rd generation fuels from algae or Jatropha) matching the following requirements:

o No significant modification of aircraft or engine is needed

o Advantages on emissions of pollutants (NOx, CO, HCs, soots...)

o Reduction of green house gas emissions (CO2 emissions will be measured and compared with standard aviation fuel)

- Performs a demonstration on a turbo-shaft engine together with a paper work extension to aero-engines

Expected Results

The main result will be

- The initial development of new open rotor technologies (blades, pitch change mechanisms, high-speed turbine, contra-rotating turbine).

- Novel concepts (vibration damping, structures and active control).

- The demonstration of the operation of alternative fuels.

- Demonstrate the potential of open rotor to greatly reduce CO2 emissions and still achieve acceptable levels of community noise

SP3 open rotor
SP3 open rotor